JP2013035960A - Resin composition for printed circuit board, prepreg and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for printed circuit boards, excellent in adhesiveness to conductive layers formed by plating in spite of small surface unevennesses, heat resistance, moisture heat resistance and combustion resistance, and suitable for forming fine circuits.SOLUTION: The resin composition includes an aralkyl type epoxy resin (A), an aralkyl type phenolic resin (B), boehmite (C), silicone powder (D) and polyvinyl acetal (E).

Description

  The present invention relates to a resin composition used for a printed wiring board, a metal foil-clad laminate using the same, and a printed wiring board.

In recent years, there has been an increasing demand for higher density printed wiring boards in electronic devices that are becoming smaller, thinner, and lighter, and accordingly, formation of fine circuits is required. Conventionally, as a circuit forming method, a subtractive method in which a metal foil is etched to form a circuit, a semi-additive method in which a conductor layer is formed on an insulating layer by plating, or the like is performed.
However, in the subtractive method, the metal foil to be used has a large unevenness on the surface of the metal foil mat that has good adhesion to the insulating layer. Due to the effect of unevenness, there is a problem that a part of the convex part tends to remain on the resin surface of the laminated board, and if the etching time is extended to completely remove this, the circuit is over-etched, and the positional accuracy and adhesion of the circuit There were problems such as a drop in power.
On the other hand, in the semi-additive method, in order to obtain an adhesive force between the insulating layer and the conductor layer, roughening of the insulating layer is performed before plating, or a large trace is formed on the surface by using a transfer mark such as a copper foil mat surface. It is necessary to increase the adhesion so that the conductor layer does not peel off. However, in the case of forming a fine circuit, there is a problem that the accuracy of circuit formation tends to be lowered if the surface irregularities are too large (see, for example, Patent Documents 1 and 2).

In Patent Document 3, by using a polyimide resin for the insulating layer, the adhesive force between the conductor layer and the insulating layer is improved, and the step of roughening the insulating layer, which has been conventionally required, is not used. A technique is described which makes it possible to keep the surface irregularities of the layer very small. However, since copper foil with a specific resin attached is used, it is more expensive than ordinary copper foil, and the adhesive strength is reduced when the roughening treatment is performed after removing the copper foil by etching. was there.
In addition, a technique for reducing surface irregularities by using a special phenol curing agent for the insulating layer is also known (see Patent Document 4). However, in this method, it is necessary to select appropriate roughening conditions, the adhesive strength varies greatly depending on the roughening conditions, and the heat resistance (moisture absorption heat resistance) of the conductor layer formed by plating after moisture absorption is poor. There was a problem such as.
Furthermore, a technique is known in which an inorganic filler obtained by treating imidazole silane on the surface of spherical silica is used (see Patent Document 5). However, this technique has a spherical particle surface and the anchor effect of plated copper is difficult to obtain, and it is difficult to obtain sufficient adhesion strength, and it is difficult to obtain sufficient combustion resistance.

JP 2003-69218 A JP 2003-249751 A JP 2007-335448 A JP 2007-254710 A International Publication No. 07/032424 Pamphlet

  The object of the present invention is for a printed wiring board that is excellent in adhesion to a conductor layer formed by plating, heat resistance, moisture absorption heat resistance and combustion resistance, and suitable for forming a fine circuit, although the surface unevenness is small. The object is to provide a resin composition. Moreover, it is providing the printed wiring board material and printed wiring board which use the resin composition.

  As a result of intensive studies to solve the above problems, the present inventors have reduced surface irregularities by using a resin composition containing an aralkyl epoxy resin, an aralkyl phenol resin, boehmite, silicone powder, and polyvinyl acetal. Nevertheless, the present inventors have found that a printed wiring board having excellent adhesion to a conductor layer formed by plating, excellent heat resistance, moisture absorption heat resistance and combustion resistance and suitable for forming a fine circuit can be obtained. did.

  The printed wiring board obtained by curing the resin composition of the present invention is excellent in adhesion to the conductor layer, heat resistance, moisture absorption heat resistance and combustion resistance.

  The resin composition of the present invention comprises an aralkyl epoxy resin (A), an aralkyl phenol resin (B), boehmite (C), silicone powder (D), and polyvinyl acetal (E).

  In another embodiment of the resin composition of the present invention, an aralkyl epoxy resin (A), a phenol resin (B), boehmite (C), silicone powder (D), polyvinyl acetal (E), and a maleimide compound (F ).

  Furthermore, in another aspect of the present invention, a prepreg obtained by curing the curable resin composition, a metal foil-clad laminate, and a printed wiring board are also provided.

  The aralkyl type epoxy resin (A) used in the present invention has an effect of improving the combustion resistance. Examples of the aralkyl type epoxy resin (A) include phenol phenyl aralkyl type epoxy resins, phenol biphenyl aralkyl type epoxy resins, and naphthol aralkyl type epoxy resins. Furthermore, among the aralkyl type epoxy resins (A), it is particularly preferable to use a phenol biphenyl aralkyl type epoxy resin, a naphthol aralkyl type epoxy resin, and a combination thereof because of excellent combustion resistance and a low thermal expansion coefficient of the cured product. These epoxy resins can be used alone or in combination of two or more.

  The blending amount of the aralkyl type epoxy resin (A) is not particularly limited, but when a total of 100 parts by mass of the components (A), (B) and (E) and the maleimide compound (F) are used, the component (A), It is preferable from a viewpoint of a thermal expansion coefficient that it is 20-60 mass parts with respect to a total of 100 mass parts of (B), (E), and (F).

The aralkyl-type phenol resin (B) used in the present invention is not particularly limited as long as two or more hydrogen atoms bonded to an aromatic ring in one molecule are substituted with a hydroxyl group, for example, naphthol aralkyl. Type phenol resin, biphenyl aralkyl type phenol resin, phenyl aralkyl type phenol resin and the like.
These aralkyl type phenol resins can be used alone or in combination of two or more.
Among these, naphthol aralkyl type phenol resins and biphenyl aralkyl type phenol resins are preferably used. The naphthol aralkyl type phenol resin is represented by the general formula (1), and is particularly preferable in terms of heat resistance and water resistance.

（式中、Ｒは水素原子又はメチル基を示し、ｎは１から５０までの整数を示す。）

(In the formula, R represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 50.)

  Moreover, biphenyl aralkyl type phenol resin is shown by General formula (2), and is especially preferable from a heat resistant and water-absorbing viewpoint.

（式中、複数存在するＲはそれぞれ独立して存在し、水素原子、炭素数１〜５のアルキル基もしくはフェニル基を表す。ｎは平均値であり１＜ｎ≦２０を表す。）

(In the formula, a plurality of R's are present independently and each represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a phenyl group. N is an average value and 1 <n ≦ 20.)

  The blending amount of the aralkyl type phenol resin is 100 parts by mass in total of the components (A), (B) and (E). When the maleimide compound (F) is used, the components (A), (B) and (E) And it is preferable from a heat resistant viewpoint that it is 5-55 mass parts with respect to a total of 100 mass parts of (F).

  In the present invention, boehmite (C) is used as the inorganic filler. Among them, amorphous boehmite is particularly preferable. When an irregular shape boehmite is used, the surface shape after the roughening treatment becomes irregular, and the anchoring effect provides good adhesion after plating or moisture absorption heat resistance after plating.

The average particle size (D50) of boehmite (C) is not particularly limited, but considering the dispersibility and surface roughness after the roughening treatment, the average particle size is preferably 0.1 to 5 μm, more preferably 0.2 to 2 μm. If the average particle diameter is within the above range, the moldability is good, and it is easy to detach after the roughening treatment, and fine surface irregularities can be formed.
Here, D50 is the median diameter (median diameter), which is the diameter at which the masses on the large side and the small side are equal when the particle size distribution of the measured powder is divided into two. Generally, it is measured by a wet laser diffraction / scattering method.
Further, it is effective to appropriately mix and use boehmite having different average particle diameters in order to increase the blending amount while maintaining moldability.

  The amount of boehmite (C) is 100 parts by mass in total of components (A), (B) and (E). When maleimide compound (F) is used, components (A), (B) and (E) And 20-500 mass parts is preferable with respect to a total of 100 mass parts of (F), More preferably, it is 30-300 mass parts, More preferably, it is 50-150 mass parts. If it is the said compounding quantity, both moldability and moisture absorption heat resistance are possible.

  Moreover, it is preferable from a viewpoint of adhesive force that the boehmite (C) in this invention is surface-treated with imidazole silane. The imidazole silane is not particularly limited as long as it is a silane coupling agent having an imidazole group. Specific examples include IS-1000, IM-1000, SP-10, IA-100A, IA-100F, IM-100F, IS-3000, and the like manufactured by Nikko Metal Co., Ltd.

  As a surface treatment method of the inorganic filler with imidazole silane, a method of treating the surface of the inorganic filler with imidazole silane in advance by a known method such as a wet method or a dry method, and a method of adding and treating in the varnish (Integral blend method), and when the inorganic filler is surface-treated with imidazole silane in the present invention, either method may be used. When treated with the integral blend method, imidazole silane tends to work as a curing accelerator for the resin, and there is a problem that the curing time (gel time) of the resin composition is shortened. Therefore, the surface of the inorganic filler is treated with imidazole silane in advance. This method is more preferable.

  As a processing amount (blending amount) of imidazole silane, when the surface of the inorganic filler is previously treated, 0.1 to 5 parts by mass is preferable with respect to 100 parts by mass of the inorganic filler, and more preferably 0. .3 to 3 parts by mass. When processing by an integral blend method, 0.1-2 mass parts is preferable with respect to 100 mass parts of inorganic fillers, More preferably, it is 0.1-1 mass part. When an inorganic filler treated with imidazole silane is used, the conductor layer formed by plating and the imidazole group form a complex, so that the anchor effect and chemical interaction due to the complex formation can exhibit excellent adhesion. it can. If the amount of imidazole silane treated (blending amount) is small, this effect is reduced. If the amount is too large, the curing time (gel time) of the resin composition is shortened as described above.

  In addition, an inorganic filler other than boehmite can be added to the resin composition of the present invention as long as the desired properties are not impaired. As other inorganic fillers, silicas such as natural silica, fused silica, amorphous silica and hollow silica, molybdenum compounds such as molybdenum oxide and zinc molybdate, from the viewpoint of further improving the flame resistance, heat resistance and moisture absorption heat resistance Alumina, aluminum hydroxide, talc, fired talc, mica, short glass fiber, spherical glass (glass fine powders such as E glass, T glass, D glass), and the like can also be added. These may be used alone or in combination of two or more.

With respect to the inorganic filler used in the present invention, a silane coupling agent other than imidazole silane, a surface treatment agent, and a wetting and dispersing agent can be used in combination.
The silane coupling agent is not particularly limited as long as it is a silane coupling agent generally used for surface treatment of inorganic substances. Specific examples include aminosilanes such as γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, epoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ -Vinyl silanes such as methacryloxypropyltrimethoxysilane, cationic silanes such as N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride, phenylsilanes, etc. It is also possible to use one kind or a combination of two or more kinds as appropriate.
The wetting and dispersing agent is not particularly limited as long as it is a dispersion stabilizer used for coatings. For example, wet dispersers such as Disperbyk-110, 111, 180, 161, BYK-W996, W9010, W903 manufactured by Big Chemie Japan Co., Ltd. may be mentioned.

As the silicone powder (D) used in the present invention, polymethylsilsesquioxane having a siloxane bond crosslinked in a three-dimensional network is finely powdered, and vinyl group-containing dimethylpolysiloxane and methylhydrogenpolysiloxane are added. The surface of a fine powder made of a polymerized fine powder or an addition polymer of vinyl group-containing dimethylpolysiloxane and methylhydrogenpolysiloxane is coated with polymethylsilsesquioxane in which a siloxane bond is crosslinked in a three-dimensional network. And those coated with polymethylsilsesquioxane in which siloxane bonds are crosslinked in a three-dimensional network on the surface of the inorganic carrier.
Silicone powder includes silicone rubber powder, silicone resin powder, and silicone composite powder, any of which can be used. Silicone powder is easily detached during the roughening treatment, and has an effect of increasing the adhesive strength of the conductor layer by an anchor effect. The shape of the particle is not particularly limited, but a spherical shape is preferable from the viewpoint of easy detachment in the roughening treatment.

  As the particle diameter of the silicone powder (D), the average particle diameter (D50) is preferably from 0.1 to 5 μm, more preferably from 0.2 to 2 μm, considering the surface irregularities after desorption.

  As a compounding quantity of silicone powder (D), when using a total of 100 mass parts of component (A), (B) and (E), and a maleimide compound (F), component (A), (B), ( 1-50 mass parts is preferable with respect to a total of 100 mass parts of E) and (F), More preferably, it is 3-30 mass parts. If it is the said compounding quantity, it can have the improvement effect of a moldability and adhesiveness. Further, if the average particle diameter is within the above range, the moldability is good, and it is easy to detach after roughening, and fine surface irregularities can be formed.

ここで計算分子量とは、ポリビニルアルコールの重合度（原料メーカーからの報告）を元に、アセタール基、アセチル基、水酸基でそれぞれの分子量とそれぞれの比率から１ユニットの平均分子量を計算し、これに重合度をかけたものである。 As the polyvinyl acetal (E) used in the present invention, known compounds such as polyvinyl butyral and polyvinyl acetoacetal can be used. Commercially available products include BL series such as S-REC BL-1, BL-5, BL-S, BM series such as BM-1, BM-2, BM-S, BX-1, BX-3, etc. BX series, BH series such as BH-3, BH-A, KS series such as KS-10, KS-1, KS-3, KS-5, KS-5Z (all manufactured by Sekisui Chemical Co., Ltd.) , Electrified butyral 3000-1, 3000-4, 3000-K, 4000-2, 5000-A, 5000-D, 6000-C, 6000-EP, 6000-AS, etc. (all manufactured by Denki Kagaku Kogyo Co., Ltd.) Can be used. Among these, from the viewpoint of adhesiveness, KS series (all manufactured by Sekisui Chemical Co., Ltd.) such as KS-10, KS-1, KS-3, KS-5, and KS-5Z, 5000-D, and 6000 -AS etc. (both manufactured by Denki Kagaku Kogyo Co., Ltd.) are preferred, and polyvinyl acetoacetal represented by the general formula (3) is preferable, and the calculated molecular weight is preferably 50,000 or less from the viewpoint of heat melting property during heating.

Here, the calculated molecular weight is based on the degree of polymerization of polyvinyl alcohol (reported by the raw material manufacturer), and calculates the average molecular weight of 1 unit from the respective molecular weights and the respective ratios for the acetal group, acetyl group, and hydroxyl group. The degree of polymerization is multiplied.

  As a compounding quantity of polyvinyl acetal (E), when using a total of 100 mass parts of component (A), (B) and (E) and a maleimide compound (F), from a heat resistant viewpoint, component (A) , (B), (E) and (F) are preferably 1 to 30 parts by mass, more preferably 2 to 10 parts by mass, with respect to 100 parts by mass in total.

The maleimide compound (F) used in the present invention is not particularly limited as long as it is a compound having one or more maleimide groups in one molecule. N-phenylmaleimide, N-hydrophenylmaleimide, bis (4 -Maleimidophenyl) methane, 2,2-bis {4- (4-maleimidophenoxy) -phenyl} propane, bis (3,5-dimethyl-4-maleimidophenyl) methane, bis (3-ethyl-5-methyl- 4-maleimidophenyl) methane, bis (3,5-diethyl-4-maleimidophenyl) methane, and the like. These bismaleimide compound prepolymers, bismaleimide compound and amine compound prepolymers, bismaleimide triazine resin, which is a reaction product of triazine, and the like can be blended, and one or two or more types can be appropriately selected. It is also possible to use a mixture.
Among these, more preferred are bis (4-maleimidophenyl) methane, 2,2-bis {4- (4-maleimidophenoxy) -phenyl} propane, bis (3-ethyl-5) from the viewpoint of heat resistance. -Methyl-4-maleimidophenyl) methane.

  As for the compounding quantity of a maleimide compound (F), 5-50 mass parts is preferable with respect to a total of 100 mass parts of component (A), (B), (E), and (F), More preferably, resin total compounding quantity It is 5-20 mass parts in 100 mass parts. By making content of a maleimide compound into this range, moisture absorption heat resistance and heat resistance can be made compatible. The maleimide compound has a high temperature required for curing, and the reaction does not proceed easily at low temperatures. By setting the content of the maleimide compound within this range, the surface of the resin composition is roughened and a pattern is formed by plating. In this case, it is easy to adjust the degree of curing at the time of lamination molding, and it is possible to easily adjust the surface roughness after the roughening treatment.

  Moreover, in the resin composition of this invention, even if it uses a hardening accelerator together in the range by which the desired characteristic is not impaired, it cannot be used. Examples of the curing accelerator that can be used include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, and triphenylimidazole, and 2- (dimethylaminomethyl) phenol. , Tertiary amines such as triethylenediamine, triethanolamine, 1,8-diazabicyclo (5,4,0) undecene-7, organic phosphines such as triphenylphosphine, diphenylphosphine, tributylphosphine, zinc octylate, etc. Metal compounds, tetraphenylphosphonium / tetraphenylborate, tetraphenylphosphonium / ethyltriphenylborate, 2-ethyl-4-methylimidazole / tetraphenylborate, N-methylmorpholine / tetraphenyl Rate, and the like, such as tetraphenyl boron salts may be mentioned of, it is possible to use a mixture of one or more appropriate.

  The blending amount of the curing accelerator is 100 parts by mass in total of the components (A), (B) and (E). When the maleimide compound (F) is used, the components (A), (B), (E) and From the viewpoint of storage stability of the prepreg, it is preferably 0.01 to 15 parts by mass with respect to 100 parts by mass in total of (F).

  In the resin composition of the present invention, other thermosetting resins, thermoplastic resins and oligomers thereof, various polymer compounds such as elastomers, and other combustible resistances, as long as the desired properties are not impaired. Combinations of high compounds and additives are also possible. These are not particularly limited as long as they are generally used. For example, examples of the compound having high combustion resistance include melamine, benzoguanamine, a phenol resin containing an aminotriazine skeleton, a nitrogen-containing compound such as a bismaleimide triazine resin, and an oxazine ring-containing compound. Additives include UV absorbers, antioxidants, photopolymerization initiators, optical brighteners, photosensitizers, dyes, pigments, thickeners, lubricants, antifoaming agents, dispersants, leveling agents, brighteners In addition, a polymerization inhibitor or the like can be used in appropriate combination as desired.

  The resin composition of the present invention can be used as a solution of a resin composition dissolved in an organic solvent, if necessary. The organic solvent is not particularly limited as long as it dissolves a mixture of various components in the present invention. Specific examples include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, polar solvents such as dimethylacetamide and dimethylformamide, and aromatic hydrocarbon solvents such as toluene and xylene. Used.

  The method for producing a prepreg of the present invention is not particularly limited as long as it is a method for producing a prepreg by combining the above resin composition and a substrate. Specifically, a method for producing a prepreg by impregnating or applying the resin composition of the present invention to a substrate and semi-curing it by a method of heating for 1 to 60 minutes in a dryer at 100 to 200 ° C. Can be mentioned. The amount of the resin composition attached to the substrate is preferably in the range of 20 to 95% by mass in terms of the resin amount of the prepreg (including the inorganic filler).

  As a base material used when manufacturing a prepreg in this invention, the well-known thing used for various printed wiring board materials can be used. Examples thereof include woven fabrics such as E glass, D glass, S glass, T glass, NE glass, quartz, and liquid crystal polyester. Although the thickness of the woven fabric is not particularly limited, it is used for laminated plate applications in the range of 0.01 to 0.3 mm. Particularly, the woven fabric subjected to the ultra-opening treatment and the plugging treatment has dimensional stability. From the aspect, it is preferable. A glass woven fabric surface-treated with a silane coupling agent such as epoxy silane treatment or amino silane treatment is preferred from the viewpoint of moisture absorption heat resistance. A liquid crystal polyester woven fabric is preferable from the viewpoint of electrical characteristics.

  The resin sheet of the present invention is prepared by a method known to those skilled in the art, for example, by preparing a resin varnish obtained by dissolving a resin composition in an organic solvent, applying the resin varnish using a support film as a support, and further heating or hot air. The organic solvent can be dried by spraying or the like to form a resin composition layer.

  The drying conditions are not particularly limited, but the drying is performed so that the content of the organic solvent in the resin composition layer is usually 10 parts by mass or less, preferably 5 parts by mass or less. Although it depends on the amount of organic solvent in the varnish, for example, a varnish containing 30 to 60 parts by mass of an organic solvent can be dried at 50 to 150 ° C. for about 3 to 10 minutes.

  The thickness of the resin composition layer formed in the resin sheet is usually not less than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm.

The metal foil-clad laminate of the present invention is formed by lamination using the above prepreg. Specifically, one or a plurality of the prepregs described above are stacked, and a metal foil is disposed on one or both sides thereof. For example, the temperature is 180 to 220 ° C., the heating time is 100 to 300 minutes, and the surface pressure is 20 to 40 kgf / cm ^2. It is manufactured by laminating and molding. Although the thickness of the metal foil to be used will not be specifically limited if it is used for printed wiring board material, it is 3-35 micrometers suitably.
Further, from the viewpoint that the metal foil mat surface is transferred to the surface of the insulating layer, and the adhesion with the plated conductor layer formed on the insulating layer can be enhanced by the uneven anchor effect transferred to the surface of the insulating layer, the Rz of the mat surface is A metal foil of 1.5 μm to 2.5 μm is suitable. Here, Rz is an index representing the surface roughness of the metal foil mat surface, and a roughness curve is usually measured by a laser microscope, and five from the average line are extracted in order from the highest peak, and five from the lowest valley are extracted in order. The average of the absolute values of is calculated and expressed.
As a method for producing a multilayer board, for example, a 35 μm copper foil is disposed on both surfaces of one prepreg of the present invention, laminated under the above conditions, an inner layer circuit is formed, and this circuit is blackened. Processing is performed to obtain an inner layer circuit board. It is also possible to form a multilayer board by combining and molding this inner layer circuit board and the prepreg of the present invention.

The prepreg and resin sheet of the present invention can be used as a build-up material. Here, the build-up is to produce a printed wiring board having a multilayer structure by repeating drilling, wiring formation, etc. for each layer of the prepreg or resin sheet.
As a specific method, the prepreg or the resin sheet of the present invention is arranged on one side or both sides of an inner layer circuit board or a metal support such as copper or aluminum, and then a metal foil or release film such as copper or aluminum is placed on the outer side thereof. Lamination is performed by repeating the operation of disposing the material.
Thereafter, generally, a hole is formed in an insulating layer formed on the wiring circuit to form a via hole and a through hole. Drilling is performed by a known method such as an NC drill, a carbon dioxide laser, a UV laser, a YAG laser, or plasma, or a combination of these methods if necessary.
As a lamination molding condition, a method of a general laminated board for printed wiring boards and a multilayer board can be applied, for example, using a multistage press, a multistage vacuum press, a laminator, a vacuum laminator, an autoclave molding machine, and the temperature is 100 to 300 ° C. The pressure is suitably selected in the range of 0.1 to 100 kgf / cm ² , and the heating time is in the range of 30 seconds to 5 hours. Further, if necessary, post-curing may be performed at a temperature of 150 to 300 ° C. to adjust the degree of curing.
Thereafter, the surface of the insulating layer is plated, but it is preferable to subject the insulating layer to a surface treatment from the viewpoint of adhesion of plating and removal of smear. As the surface treatment, there are a roughening treatment, a silane coupling treatment, and the like. In particular, the roughening treatment is performed from the viewpoint of improving the adhesion of plating. In this case, since the roughening state varies depending on the difference in the degree of cure of the resin composition, it is preferable to select optimum conditions for the lamination molding conditions in combination with the subsequent roughening treatment conditions and plating conditions.

Next, the roughening process will be described in detail. This process also serves to remove smears generated by the drilling process. The roughening treatment includes a surface insulating layer swelling step with a swelling agent for improving wettability, a surface roughening and smear dissolving step with an oxidizing agent, and a neutralizing step with a reducing agent.
As the swelling agent in the swelling step, any material may be used as long as it improves the wettability of the surface insulating layer and can swell to the extent that oxidative decomposition is promoted in the next roughening step. Etc. are used.
A permanganate solution or the like is used as the oxidizing agent in the surface roughening and smear dissolving step with the oxidizing agent. In addition to these methods called wet desmearing, known roughening treatments such as dry desmear by plasma treatment or UV treatment, mechanical polishing by buffing, sandblasting, etc. can also be used in combination. As specific examples of the permanganate solution, a potassium permanganate aqueous solution and a sodium permanganate aqueous solution are preferably used.
As the reducing agent in the neutralization step, an amine-based reducing agent can be used, and examples thereof include acidic reducing agents such as hydroxylamine sulfate aqueous solution, ethylenediaminetetraacetic acid aqueous solution, and nitrilotriacetic acid aqueous solution.

  In forming fine wiring, it is preferable that the surface roughness after the roughening treatment is small. Specifically, the Rz value is preferably 4.0 μm or less, more preferably 2.0 μm or less. Since the surface irregularities after the roughening treatment are determined by the degree of cure of the resin composition and the roughening treatment conditions, it is preferable to select optimum conditions for obtaining the desired surface irregularities.

  Next, the plating process after the roughening treatment will be described in detail. As a pattern forming method by plating, known methods such as a semi-additive method, a full additive method, a method of forming a conductor layer by plating in advance and forming a pattern by a subtractive method can be used. The semi-additive method is preferred.

  The pattern formation by plating is preferably performed after plating because the adhesive strength is increased by drying after plating. The pattern formation by the semi-additive method is performed by combining electroless plating and electrolytic plating. In this case, it is preferable to perform drying after the electroless plating and after the electrolytic plating. Drying after electroless is preferably performed at 80 to 180 ° C. for 10 to 120 minutes, and drying after electrolytic plating is preferably performed at 130 to 220 ° C. for 10 to 120 minutes.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1
15 parts by mass of naphthol aralkyl resin represented by formula (1) (SN495V2, manufactured by Nippon Steel Chemical Co., Ltd.), biphenyl aralkyl type phenol resin represented by formula (2) (KAYAHARD GPH-103, manufactured by Nippon Kayaku, hydroxyl equivalent: 231 g / eq .) 15 parts by mass, biphenyl aralkyl type epoxy resin (NC-3000-FH, epoxy equivalent: 321 g / eq., Manufactured by Nippon Kayaku), 45 parts by mass, naphthalene tetrafunctional epoxy resin (EXA-4710, manufactured by DIC) 4 parts by mass Parts are dissolved and mixed with methyl ethyl ketone, 120 parts by weight of boehmite (APYRAL AOH60, manufactured by Nabaltec) and 10 parts by weight of silicone resin powder (MSP-N050, manufactured by Nikko Rica) are added and dispersed with stirring for 1 hour using a homogenizer. It was. Furthermore, 3 parts by mass of polyvinyl acetoacetal (KS-10, manufactured by Sekisui Chemical Co., Ltd.) was dissolved in toluene and added, and 3 parts by mass of a triazine skeleton-containing phenolic curing agent (LA3018, manufactured by DIC), imidazole ( Varnish 1 was obtained by adding 0.02 parts by mass of 2E4MZ (manufactured by Shikoku Chemicals Co., Ltd.) and stirring. This varnish 1 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Example 2)
30 parts by mass of naphthol aralkyl resin, 15 parts by mass of cresol novolac resin (KA-1165, manufactured by DIC), 15 parts by mass of novolac type epoxy resin (N770, manufactured by DIC), 30 parts by mass of biphenyl aralkyl type epoxy resin, 4-functional naphthalene 4 parts by mass of epoxy resin was dissolved and mixed with methyl ethyl ketone, 120 parts by mass of boehmite (APYRAL AOH60, manufactured by Nabaltec) and 5 parts by mass of silicone resin powder were added and dispersed with stirring for 1 hour in a homogenizer. Furthermore, 5 parts by mass of polyvinyl acetoacetal was dissolved in toluene and added, and 3 parts by mass of a triazine skeleton-containing phenolic curing agent and 0.02 parts by mass of imidazole were added and stirred to obtain varnish 2. This varnish 2 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Example 3)
15 parts by mass of naphthol aralkyl resin, 15 parts by mass of phenol novolac resin (TD-2090, manufactured by DIC), 15 parts by mass of cresol novolac resin, 15 parts by mass of novolac type epoxy resin, and 30 parts by mass of biphenyl aralkyl type epoxy resin are dissolved in methyl ethyl ketone. After mixing, 150 parts by mass of boehmite (APYRAL AOH60, manufactured by Nabaltec) and 5 parts by mass of silicone resin powder were added, and the mixture was dispersed with stirring for 1 hour using a homogenizer. Furthermore, 5 parts by mass of polyvinyl acetoacetal was dissolved in toluene and then added, and 3 parts by mass of a triazine skeleton-containing phenolic curing agent and 0.02 parts by mass of imidazole were added and stirred to obtain varnish 3. This varnish 3 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

Example 4
15 parts by mass of naphthol aralkyl resin, 15 parts by mass of biphenyl aralkyl type phenol resin, 45 parts by mass of biphenyl aralkyl type epoxy resin, 4 parts by mass of naphthalene tetrafunctional epoxy resin, 17 parts by mass of maleimide compound (BMI-70, manufactured by KAI Kasei) Then, 120 parts by mass of boehmite (APYRAL AOH60, manufactured by Nabaltec) and 10 parts by mass of silicone resin powder were added and dispersed with stirring for 1 hour in a homogenizer. Furthermore, 3 parts by mass of polyvinyl acetoacetal was dissolved in toluene and then added, and 3 parts by mass of a triazine skeleton-containing phenolic curing agent and 0.02 parts by mass of imidazole were added and stirred to obtain varnish 4. This varnish 4 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Example 5)
15 parts by mass of biphenyl aralkyl type phenol resin, 15 parts by mass of phenol novolac resin, 15 parts by mass of cresol novolac resin, 25 parts by mass of biphenyl aralkyl type epoxy resin, 25 parts by mass of novolac type epoxy resin, 4 parts by mass of naphthalene tetrafunctional epoxy resin Then, 150 parts by mass of boehmite (APYRAL AOH60, manufactured by Nabaltec) and 10 parts by mass of silicone resin powder were added and dispersed with stirring for 1 hour in a homogenizer. Furthermore, 5 parts by mass of polyvinyl acetoacetal was dissolved in toluene and then added, and 3 parts by mass of a triazine skeleton-containing phenolic curing agent and 0.02 parts by mass of imidazole were added and stirred to obtain varnish 5. This varnish 5 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Example 6)
15 parts by mass of biphenyl aralkyl type phenol resin, 15 parts by mass of cresol novolac resin, 15 parts by mass of biphenyl aralkyl type epoxy resin, 30 parts by mass of novolac type epoxy resin, 4 parts by mass of naphthalene tetrafunctional epoxy resin, 17 parts by mass of maleimide compound with methyl ethyl ketone 150 parts by weight of boehmite (APYRAL AOH60, manufactured by Nabaltec), which was surface-treated with 0.5% by mass of imidazole silane (manufactured by IS-1000 Nikko Metal), and 5 parts by weight of silicone resin powder were added after dissolution and mixing. The mixture was dispersed with a homogenizer with stirring for 1 hour. Further, 3 parts by mass of polyvinyl acetoacetal was dissolved in toluene and then added, and 3 parts by mass of a triazine skeleton-containing phenolic curing agent and 0.02 part by mass of imidazole were added and stirred to obtain varnish 6. This varnish 6 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Example 7)
15 parts by mass of naphthol aralkyl resin, 15 parts by mass of biphenyl aralkyl type phenol resin, 45 parts by mass of biphenyl aralkyl type epoxy resin, 4 parts by mass of naphthalene tetrafunctional epoxy resin and 17 parts by mass of maleimide compound are dissolved and mixed with methyl ethyl ketone, and boehmite (APYRAL AOH60 120 parts by mass of Nabaltec) and 10 parts by mass of silicone resin powder were added and dispersed with stirring with a homogenizer for 1 hour. Furthermore, 3 parts by mass of polyvinyl acetoacetal was dissolved in toluene and then added, and 3 parts by mass of a triazine skeleton-containing phenolic curing agent and 0.02 parts by mass of imidazole were added and stirred to obtain varnish 7. This varnish 7 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Comparative Example 1)
15 parts by mass of naphthol aralkyl resin, 15 parts by mass of biphenyl aralkyl type phenolic resin, 45 parts by mass of biphenyl aralkyl type epoxy resin, and 4 parts by mass of naphthalene tetrafunctional epoxy resin are dissolved and mixed with methyl ethyl ketone, and spherical silica (SFP-130MC Denka) 120 Part by mass and 10 parts by mass of silicone resin powder were added and dispersed with stirring by a homogenizer for 1 hour. Furthermore, 3 parts by mass of polyvinyl acetoacetal was dissolved in toluene and then added, and 3 parts by mass of a triazine skeleton-containing phenolic curing agent and 0.02 parts by mass of imidazole were added and stirred to obtain varnish 8. This varnish 8 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Comparative Example 2)
30 parts by mass of phenol novolac resin, 15 parts by mass of cresol novolac resin, 45 parts by mass of novolac type epoxy resin, and 4 parts by mass of naphthalene tetrafunctional epoxy resin are dissolved and mixed with methyl ethyl ketone, and 0.5% by mass of imidazole silane with respect to the inorganic filler. 120 parts by mass of spherical silica (SFP-130MC Denka) that was surface-treated with (IS-1000 Nikko Metal) and 5 parts by mass of silicone resin powder were added and dispersed with stirring for 1 hour in a homogenizer. Furthermore, 3 parts by mass of polyvinyl acetoacetal was added after being dissolved in toluene, and 3 parts by mass of a triazine skeleton-containing phenol-based curing agent and 0.02 parts by mass of imidazole were added and stirred to obtain varnish 9. This varnish 9 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm-thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Comparative Example 3)
In Comparative Example 2, 15 parts by mass of naphthol aralkyl resin, 15 parts by mass of biphenyl aralkyl type phenol resin, 45 parts by mass of biphenyl aralkyl type epoxy resin, 4 parts by mass of naphthalene tetrafunctional epoxy resin, and 17 parts by mass of maleimide compound were dissolved and mixed with methyl ethyl ketone. 120 parts by weight of the spherical silica used and 10 parts by weight of the silicone resin powder were added and dispersed with stirring by a homogenizer for 1 hour. Furthermore, 3 parts by weight of polyvinyl acetoacetal was dissolved in toluene and then added, and 3 parts by weight of a triazine skeleton-containing phenolic curing agent and 0.02 parts by weight of imidazole were added and stirred to obtain varnish 10. This varnish 10 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Comparative Example 4)
15 parts by mass of a biphenyl aralkyl type phenol resin, 15 parts by mass of a phenol novolac resin, 45 parts by mass of a novolac type epoxy resin, 4 parts by mass of a naphthalene tetrafunctional epoxy resin, and 17 parts by mass of a maleimide compound are dissolved and mixed with methyl ethyl ketone. 150 parts by weight of spherical silica and 5 parts by weight of silicone resin powder were added and dispersed with stirring with a homogenizer for 1 hour. Furthermore, 5 parts by mass of polyvinyl acetoacetal was dissolved in toluene and then added, and 3 parts by mass of a triazine skeleton-containing phenolic curing agent and 0.02 parts by mass of imidazole were added and stirred to obtain varnish 11. This varnish 11 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Comparative Example 5)
16 parts by mass of naphthol aralkyl resin, 15 parts by mass of phenol novolac resin, 15 parts by mass of cresol novolac resin, 45 parts by mass of biphenyl aralkyl type epoxy resin, and 4 parts by mass of naphthalene tetrafunctional epoxy resin are dissolved and mixed with methyl ethyl ketone, and boehmite (APYRAL AOH60, 120 parts by mass) (manufactured by Nabaltec) was added and dispersed with stirring with a homogenizer for 1 hour. Furthermore, 3 parts by weight of polyvinyl acetoacetal was dissolved in toluene and then added, and 3 parts by weight of a triazine skeleton-containing phenolic curing agent and 0.02 parts by weight of imidazole were added and stirred to obtain varnish 12. This varnish 12 was diluted with methyl ethyl ketone, impregnated onto a 0.1 mm thick E glass woven fabric, and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

(Comparative Example 6)
15 parts by mass of a biphenyl aralkyl type phenol resin, 15 parts by mass of a phenol novolac resin, 15 parts by mass of a cresol novolac resin, 45 parts by mass of a biphenyl aralkyl type epoxy resin, and 4 parts by mass of a naphthalene tetrafunctional epoxy resin are dissolved and mixed with methyl ethyl ketone, and boehmite (APYRAL 150 parts by mass of AOH 60 (manufactured by Nabaltec) and 10 parts by mass of silicone resin powder were added and dispersed with stirring by a homogenizer for 1 hour. Furthermore, 3 parts by mass of a triazine skeleton-containing phenolic curing agent and 0.02 parts by mass of imidazole were added and stirred to obtain varnish 13. This varnish 13 was diluted with methyl ethyl ketone, impregnated and coated on a 0.1 mm thick E glass woven fabric, and dried by heating at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 47.5 mass%.

<Creation of metal foil-clad laminate>
Eight prepregs obtained in Examples 1 to 7 and Comparative Examples 1 to 6 were stacked, and the shiny surface of 12 μm thick electrolytic copper foil (JTC-LP, manufactured by Nikko Metal Co., Ltd.) was placed on the prepreg side. Lamination was performed at a pressure of 30 kgf / cm ² and a temperature of 200 ° C. for 50 minutes to obtain a copper clad laminate having an insulating layer thickness of 0.8 mm.

<Wet roughening treatment and conductor layer plating>
The surface copper foil of the upper copper clad laminate was removed by etching, and immersed in a swelling treatment solution (OPC-B103 pre-etched 400 ml / L, sodium hydroxide 13 g / L) manufactured by Okuno Pharmaceutical Co., Ltd. at 60 ° C. for 5 minutes. Next, it was immersed for 25 minutes at 80 ° C. in a roughening treatment solution (OPC-1540MN 100 ml / L, OPC-1200 Epochetch 100 ml / L) manufactured by Okuno Pharmaceutical. Finally, a wet roughening treatment was performed in a neutralization treatment solution (OPC-1300 Neutrizer 200 ml / L) manufactured by Okuno Pharmaceutical Co., Ltd. for 5 minutes at 45 ° C. Thereafter, in an electroless copper plating process manufactured by Okuno Pharmaceutical Co., Ltd. (used chemical names: OPC-370 Condyclean M, OPC-SAL M, OPC-80 Catalyst, OPC-555 Accelerator M, ATS Ad Copper IW) About 0.5 μm of electroless copper plating was applied, followed by drying at 130 ° C. for 1 hour. Subsequently, electrolytic copper plating was performed so that the thickness of the plated copper was 20 μm, and drying was performed at 180 ° C. for 1 hour.

The evaluation results of the laminate obtained by the above operation are shown in Table 1. The measurement method used was the method described below.
(Measuring method)
1) The surface layer copper foil of the copper clad laminate above the glass transition temperature was removed by etching, and the sample after baking at 220 ° C. for 1 hour was measured according to the JIS C6481 DMA method.
2) The sample from which the surface copper foil of the copper clad laminate on the flame resistance was removed by etching was evaluated according to the UL94 vertical combustion test method.
3) Plated copper adhesive strength A laminated plate coated with plated copper was prepared, and the adhesive strength of the plated copper was measured according to JIS C6481. Average value measured three times. Regarding the sample swollen by drying after electrolytic copper plating, the evaluation was performed using the non-swollen portion.
4) Plating copper heat resistant plating In the same way as the measurement of copper adhesive strength, a laminated plate with plated copper was prepared, cut into 50 mm x 50 mm square, floated on 280 ° C solder for 30 minutes, and delamination Presence / absence was determined by visual judgment.
○: No abnormality at all ×: Delamination occurred while floating for 0 to 30 minutes 5) Plating copper hygroscopic heat resistant plating In the same manner as the measurement of copper adhesive strength, a laminated plate with plated copper was prepared, and 50 mm After cutting to × 50 mm square, a sample was prepared by removing plated copper other than half of one side by etching. The sample was treated with a pressure cooker tester (PC-3 type manufactured by Hirayama Seisakusho) at 121 ° C. and 2 atm for 1, 3, and 5 hours, and then immersed in a solder bath at 260 ° C. for 30 seconds to change the appearance. The presence or absence of abnormality was visually observed. A three-sheet test was performed, and for each sheet, a mark indicating no abnormality was indicated as “◯”, and a mark indicating blistering was indicated as “X”.
6) Surface roughness The surface copper foil of the produced copper clad laminate was removed by etching, and after the desmeared sample was dried at 130 ° C. for 1 hour, a laser microscope (VK-9500 made by Keyence) was used. The Ra (10-point average roughness) of the surface of the insulating layer was determined from the 3000-fold image.

  The evaluation results of the metal foil-clad laminate obtained by the examples including all of the aralkyl type epoxy resin (A), the aralkyl type phenol resin (B), boehmite (C), silicone powder (D) and polyvinyl acetal (E) are The metal foil-clad laminate obtained by the comparative example lacking one or more of the above components was superior to the evaluation results.

Claims (23)

  A resin composition comprising an aralkyl epoxy resin (A), an aralkyl phenol resin (B), boehmite (C), silicone powder (D), and polyvinyl acetal (E).   The resin composition according to claim 1, wherein the aralkyl type phenol resin (B) is a naphthol aralkyl type phenol resin.   The resin composition according to claim 1, wherein the aralkyl type phenol resin (B) is a biphenyl aralkyl type phenol resin.   The resin composition according to claim 1, wherein the aralkyl type phenol resin (B) is a combination of a naphthol aralkyl type phenol resin and a biphenyl aralkyl type phenol resin.   The resin composition according to any one of claims 1 to 4, wherein the polyvinyl acetal resin (E) is a polyvinyl acetoacetal resin.   The resin composition according to claim 1, further comprising a maleimide compound (F).   The resin composition according to any one of claims 1 to 6, wherein the boehmite (C) is surface-treated with imidazole silane.   When the blending amount of the aralkyl epoxy resin (A) is 100 parts by mass of the components (A), (B) and (E), and the maleimide compound (F) is used, the components (A) and (B) The resin composition according to claim 1, wherein the resin composition is 20 to 60 parts by mass with respect to 100 parts by mass in total of (E) and (F).   When the blending amount of the aralkyl type phenol resin (B) is 100 parts by mass of the components (A), (B) and (E) and the maleimide compound (F) is used, the components (A) and (B) The resin composition according to claim 1, wherein the resin composition is 5 to 55 parts by mass with respect to 100 parts by mass in total of (E) and (F).   When the amount of the boehmite (C) is 100 parts by mass in total of the components (A), (B) and (E) and the maleimide compound (F) is used, the components (A), (B), (E The resin composition according to any one of claims 1 to 9, which is 20 to 500 parts by mass with respect to 100 parts by mass of the total of (A) and (F).   When the blending amount of the silicone powder (D) is 100 parts by mass of the components (A), (B) and (E), and the maleimide compound (F) is used, the components (A), (B), ( The resin composition according to any one of claims 1 to 10, which is 1 to 50 parts by mass relative to 100 parts by mass of E) and (F) in total.   When the blending amount of the polyvinyl acetal (E) is 100 parts by mass in total of the components (A), (B) and (E), and the maleimide compound (F) is used, the components (A), (B), ( It is 1-30 mass parts with respect to a total of 100 mass parts of E) and (F), The resin composition in any one of Claims 1-11.   A prepreg obtained by impregnating or coating the base material with the resin composition according to claim 1.   A resin sheet obtained by coating the solution of the resin composition according to any one of claims 1 to 12 on a surface of a metal foil or film and drying the solution.   A metal foil-clad laminate obtained by laminating at least one prepreg according to claim 13 and placing a metal foil on one or both sides thereof.   The metal foil-clad laminate according to claim 15, wherein Rz of the metal foil mat surface is 1.5 μm to 2.5 μm.   A printed wiring board using the prepreg according to claim 13 as a build-up material.   A printed wiring board obtained by etching a metal foil of the metal foil-clad laminate according to claim 15, subjecting the metal foil to a pattern treatment by plating.   A printed wiring board using the resin sheet according to claim 14 as a build-up material.   The printed wiring board according to claim 19, wherein the printed wiring board is surface-treated and patterned by plating.   21. A printed wiring board, wherein the surface treatment according to claim 18 or 20 is a desmear treatment comprising a roughening treatment with a swelling agent, an alkaline oxidizing agent, and a neutralization treatment with an acidic reducing agent.   The printed wiring board according to claim 18 or 20, wherein the pattern formation by plating is performed by electrolytic copper plating after electroless copper plating, and then by a semi-additive method.   The printed wiring board according to claim 18 or 20, wherein pattern formation by plating is performed by electrolytic copper plating after electroless copper plating and then by a subtractive method.